Histology 2 (Exam 1) Flashcards
What is the rER continuous with
nuclear envelope
What type of cells will have highly developed rER
secretory cells:
osteoblasts and glandular cells
What is the function of the rER
involved in the synthesis of secreted and membrane proteins
What are ribosomes composed of
proteins and rRNA
Where are ribosomes found
can be free in the cytoplasm or membrane bound to rER
What is the function of ribosomes
involved in protein synthesis
What are the functions of the sER
lipid metabolism
detoxification
steroid synthesis
What is the function of sER in skeletal muscle
Ca2+ storage
What are sER in skeletal muscle called
sarcoplasmic reticulum
How might sER change in the liver of a patient on drugs or alcohol
more sER in liver
What is the function of the inner membrane of mitochondria
increased surface area of inner membrane increases integral membrane proteins
Where are mitochondrial proteins produced
imported from host cell
List nonliving inclusions that can be found within the cells
secretory granules
stored energy (glycogen and fat)
pigments (hemoglobin and melanin)
crystals (sertoli and leydig cells)
What are the main components of the cytoskeleton
microtubules
actin
intermediate filaments
What is the function of microtubules in the cytoskeleton
transport and movement
What is the function of actin in the cytoskeleton
membrane structure and motility
WHat is the thinnest filament
actin
What is the function of intermediate filaments in the cytoskeleton
mechanical strength
What is the structure of microtubules
gamma tubulin ring with alternating alpha and beta tubulin molecules bound to GTP/GDP
What are the ends on a microtubule
growing end (+) non growing end (-)
What cell processes are microtubules involved in
cell division: alignment/separation of chromosomes during cell division
vesicular transport
movement of cilia/flagella
Which end of microtubules will be in contact with gamma tubulin
- end
What proteins are involved in transport along microtubules
dyneins and kinesins
What is the role of dyneins
motor proteins that move towards the - end of microtubule
What is the role of kinesin in transport
motor proteins that move towards the + end of microtubules
What is the role of centrosomes
Align mitotic spindle during cell division
What are basal bodies
basal bodies are at the base of each flagellum and cilium and organize their development (microtubule organizing center)
What is the structure of a centriole
9 triplets of microtubules arranged in a circle
What is at the center of a basal body
centrioles
2 at 90 degrees
What is a centrosome
2 centrioles paired at 90 degrees
What causes Kartagener’s syndrome
immobilization of cilia
What are symptoms of Karagener’s syndrome
infertility and respiratory infections
What structure does the chemotherapy agent Taxol affect
microtubules
How does Taxol affect microtubules
prevents depolymeration
How does Taxol have an effect on cancer
prevents separation of sister chromatids and thus halts cell division
What structures do Vinblastine and Vincristine affect
Microtubules
How does Vinblastine and Vincristine affect microtubules
inhibits formation of mitotic spindle for cell division
What are vinblastine and vincristine used for
chemotherapy
What are cilia composed of
microtubules
How does actin assemble
spontaneously without a gamma ring
At what end will depolymerization and polymerization occur on actin
+ end= polymerization
- end = depolymerization
What are the functions of actin filaments
cell shape and structure form microvilli anchorage and movement extension of cell processes locomotion
Where is phalloidin found
poisonous mushrooms
What are the effects of phalloidin
prevents depolymerization of actin by binding to F-acin
How does phalloidin change actins structure
makes it longer and stable
What is the effects of cytochalasin B and D
Prevents polymerization of actin
How does cytochalasin B and D effect the cells
inhibits lymphocyte migration, phagocytosis, and cell division
What part of the cell cycle is actin especially important in
telophase
What is the function of intermediate filaments
mechanical strength
cell-cell and cell-matrix junctions
What are the classes of intermediate filaments
Keratins
Vimentins
Neurofilamints
Lamins
Where are keratins found
all epithelial cells in the cytoplasm
Where are Vimentins found
fibroblasts and neurons in the cytoplasm
Where are Neurofilaments found
in neurons in the cytoplasm
Where are Lamins found
most differentiated cells, all nucleated cells
in the nuclear
What diseases may lead to accumulation of intermediate filaments
Alcoholic liver cirrhosis
Alzheimer’s disease
What filaments accumulate in Alcoholic liver cirrhosis
keratins forming mallory bodies
What filaments accumulate in Alzheimer’s disease
neurofilaments leading to neurofibrillary tangles
What are mallory bodies
accumulation of keratin in alcoholic liver cirrhosis
What is heterochromatin
darker staining
more condenses
not transcriptionally active
What is euchromatin
lighter staining
less condensed
transcriptionally active
What is the function of the nuclear lamina
maintains shape of nucleus and organizes chromatin
scaffolding for chromosomes and nuclear pores
What is the structure of the nuclear lamina
lamin proteins (intermediate filaments)
What structure is the nuclear envelope
two bilayer membranes separated by a perinuclear space
What is the perinuclear space of the nuclear envelope continuous with
rER
What diseases are associated with impaired nuclear lamina architecture
Progeria
Emery-Dreifuss muscular dystrophy
What is defective in Progeria
Lamin A/C
What is defective Emery-Dreifuss muscular dystrophy
lamins, lamin receptors, and emerin
What is chromatin
DNA and structural proteins (histones) packaged to fit in the nucleus
How many chromosomes do humans have
23 pairs
1 sex pair
22 autosomal pairs
What is the function of telomerase
repeatedly adds nucleotide sequences to the telomere ends to prevent shortening of chromatids
What can telomerases play a role in clinically
oncogenesis
What is a barr body
deactivated, shriveled up X chromosome
in chromosomes with two Xs
Where are barr bodies found
near the nuclear envelope
What occurs in the nucleolus
rRNA synthesis
assembly of ribosomes
regulation of the cell cycle
How can the cell cycle be regulated through the nucleolus
through nucleostemin p-53 binding protein
What is the target of viruses within a cell
nucleolus
What is nucleostemin
protein that regulates cell cycle and influences cell differentiation
From a clinical aspect, what can nucleostemin impact
play a role in malignancy
What is static cell renewal
cell no longer replicates
CNS and cardiac
What is stable cell renewal
cell replicates when needed
smooth muscle, endothelial cells
What are slow growing cell exampels
fibroblasts
epithelial cells of the eye lens
What are fast growing cell examples
blood cells
epithelial cells
What are the stages of the cell cycle
Gap 1 phase
S phase
G2 phase
Mitosis
What is GTD phase
terminal differntiation, cells no longer divide
WHat is G0 phase
cells are in stable phase of cell division
What is S phase
DNA synthesis
What is G2 phase
growth and reorganization
accumulation of energy for division
What is G1 phase
proteins needed for DNA synthesis
What is the fastest stage of the cell cycle
mitosis
What effect might a defect in cell cycle checkpoints lead to
malignant transformation or aberrant chromosome segregation
What are protein complexes associated with cell cycle regulation
cyclin kinase and cyclin
How are cyclin levels throughout the cycle
cyclin levels change
What is cyclin kinase levels throughout the cycle
kinase levels do not change, but depend on cyclin
Which is more important in regulating the cell cycle
cyclin kinases
What is the outcome of mitosis
2 daughter cells with exact DNA sequences and chromosome number
What is the outcome of meiosis
Four genetically different cells, with half the number of chromosomes as the original cell
haploid cells
What is the produce of male meiosis
4 spermatids
What is the product of female meisosi
1 oocyte and 3 polar bodies
What is necrosis
cell swelling and death
What is apoptosis
organized cellular death
What causes necrosis
pathology, caused by damage to the cell leads to cell swelling and inflammation
What is faster necrosis or apoptosis
apoptosis